BEFORE DYNAMIC ANALYSIS TECHNIQUES On November 7, 1940, at approximately 11:00 AM, the first Tacoma
Narrows suspension bridge collapsed due to wind-induced vibrations.
Situated on the Tacoma Narrows, near the city of
Tacoma, Washington, the bridge had only been open for traffic a few
months. Within a short space of time the bridge collapsed.
HOW CAN A DYNAMIC ANALYSIS HELP ME?
is typically used to design out potential noise and vibration
problems, or to evaluate the impact of transient loads. Modal analysis
is used to identify natural frequencies, and enables the designer to
avoid excitation and eliminate excessive vibration. Animations are
easily produced to provide valuable insight into how the structure
will behave when excited. Harmonic response analysis is used to
determine the steady-state response of a linear structure to
sinusoidal loads, and enables the evaluation of resistance to
sustained forced vibration. Transient dynamic analysis is used to
determine the response to general time-dependent loads. Typical
applications include seismic or explosive events. Rotordynamic
analysis is important when designing or troubleshooting rotating
systems. By modelling the rotating geometry and its dynamic
characteristics, such as stiffness and damping, the critical speeds
can be predicted. Design adjustments can then be made to avoid
continuous running at those speeds.